When placed in a conventional table lamp most LED light bulbs, including this LG bulb, have a tendency to illuminate upwards. This is because of the horizontal placement of the LED emitters inside. The Philips bulbs use three vertically oriented LED panels to alleviate this concern. However, in an over the shoulder reading lamp or a task lamp, the bulb illuminates uniformly and does not throw any heat on the illuminated target.
The LG light bulb illuminates mostly upwards because of the horizontal
placement of the LED panel inside the bulb (click on image to enlarge).
The design of table lamps is meant to accommodate the Edison light bulb, which emits light in all directions. The spindle allows the electrical cord to reach the bulb and the lamp shade serves as a diffuser. The shade, being open top and bottom, allows the natural convection to take away the unwanted heat. It also enables easy replacement of the short-lived bulb. The electric table lamp has evolved over more than a century to accommodate the light bulb and is very different from its precursor luminaire, the oil lamp.
The very first electric lamps were not necessarily very effective or very popular, yet their advantages prevailed and the use of oil lamps waned. Over time, and probably rather rapidly, lamps will evolve to adapt to the peculiarities of the LED sources. When LED light sources achieve lifetimes in decades, replacing them will no longer be a concern and luminaires will take on various forms and shapes. Meanwhile, forcing LEDs to assume the Edison format is akin to forcing a square peg into a round hole.
Nevertheless, Strategies Unlimited predicts that "the global market for replacements for legacy lighting sources will grow from $2.2 billion in 2011 to $3.7 billion in 2016." Indeed, LED light bulbs provide very pleasant illumination, much more agreeable than compact fluorescent bulbs, and they will be adopted eagerly. They outlast CFLs, contain no mercury, and are instant-on. One annoying trait of CFLs is that they take a relatively long time to reach their maximum level of illumination.
LED light bulbs are complex electronic devices. The LEDs themselves are semiconductor diodes, wanting a low voltage DC supply, typically around 3 volts. Common household supply is 110V or 220V AC depending on geographic location. The LG bulb is not dimmable. More expensive models are dimmable, although newer types of dimmers may be needed. Like CFL bulbs, LED bulbs have a small circuit board stuffed inside the neck.
I have no problem at all with retaining the standard Edison base. For one thing, it means that using LED bulbs does not mandate buying all new light fixtures for the entire house. Hardly something to ignore.
For another, it means that when you change the LED bulb, which on average should be several years, the electronics are trivially easily changed along with the bulb. Without having to go through an INEVITABLY more complicated procedure, should the electronics, part of the lamp fixture itself, go bad.
Besides, it wouldn't be all that hard to have the LED part of the bulb be a separate piece from the Edison base which houses the electronics. Snap the LED glass part onto the Edison base. Assuming the electronics are good enought to last way longer than the LED. That still makes the system fully backward compatible AND totally user serviceable.
Parenthetically, I'm not saying that everyone prefers a system that is fully backward compatible and totally user serviceable. We could create a whole new industry of previously unnecessary lamp maintenance shops, to artifically improve employment opportunities.
I wonder what the mtbf is for the led's vs the control electronics? As mentioned before it is strange that the new bulbs are made to look like the old - what about a new socket for the led's that will fit in a base housing the electronics - then we could get away from the standard antiquated screw in base... I have started to replace them although EDN's chart had a 90% manufacturing cost drop from now until 2015 - the old early adopter costs to get it going, or wait and hope others drive the industry and thus the costs down.....
There is one aspect of LED lamps that uniquely sets them apart - No RF interference. For a long time now, RF interference (particularly in the VHF / UHF range) from fluorescent lamps is well known. LED for the first time offers a clean source without this interference. It is major plus for many outdoor public areas. In addition, it would be a major plus even for business offices where public safety personnel are needed (such as EMS, Fire etc).
The "fixture" (such as the lamp base) could have the power conversion circuit (from wall 120/240VAC) and the "bulb" could be primarily the LED's + diffuser. The packaging often wouldn't be as tight physically and there could be one power conversion circuit for several "bulbs". The LED bulbs could be replaced or potentially the lamp base's electronic module could be modular and replaceable. I don't see why the power circuit would be very expensive, especially given the possibility of much more packaging freedom.
We should get a teardown of the driver and PFC or whatever else they use to understand this aspect better.
You are correct the added feature about the LED light bulb. As we know the Triac dimming and PFC features. The PFC is 100 % for the incandescent light bulb but when you use the Triac to dim the light, it burns the power away. LED light bulb doesn't and i can maintain PFC to reduce the E-cap which the conventional light bulbs needed.
The bottom line is improvement with the LED light bulb.
1. get rid of the E-cap and have high PFC.
2. While dimming, it saves the power,not burns away the power like the conventional light bulb.
3. there are quite a lot of protections of the circuits which doesn't exist in the conventional light bulbs. The extra protections are hidden in the LED drivers like the in-rush current limit, soft start, short circuit protection(over current), and over temperature protection..etc.
4. for the extra cost, you can have the color temperature control light bulb, to have the red LEDs to adjust the color temperature.
5. The new HV-LEDs give you higher efficacy and Lumens with less current.
"Does anyone know the temperature of the circuitry in a GU10 or A19/E27 LED bulb?"
I don't know the internal temperature but the hottest "60W" A-19 I've used is the Philips. The external heat sink temperature is about 122 deg F with a 73 deg ambient.
Though the life of electrolytics at the elevated temperatures in an LED are a concern, my greater concern are the life of the electrolytics in a SmartMeter. Last summer, 105-110 deg ambient temps were the norm here in Texas. The meters are "designed for 20+ year life." (Landis-Gyr spec sheet.) That's 175,200 hours in temps ranging from 15-110 deg F 24/7/365 x 20.
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